I am constructing a small wind generator for a college project. I want the 0.1 V AC output of the generator to charge a battery. To do this, I need to convert the current into DC. I am familiar with things like bridge rectifier circuits, but the smallest diodes I can find have a forward "turn on" voltage of about 0.25 V, which will not even turn on for my small 0.1V signal. What are my options for getting the AC current output into the battery? Thanks